Lubricating oil containing overbased sulfurized calcium alkylphenolate



3,474,035 ITUBRICATING OIL CONTAINING OVERBASED SULFURIZED CALCIUM ALKYLPHENOLATE James G. Dadura, Fishkill, N.Y., assignor to Texaco Inc, New York, N.Y., a corporation of Delaware No Drawing. Filed Mar. 20, 1967, Ser. No. 624,193

Int. Cl. CIlOm 1/38 US. Cl. 25.2-42.7 5 Claims ABSTRACT OF THE DISCLOSURE A lubricating oil composition containing a partially hydrolyzed overbased sulfurized calcium alkylphenolate detergent of antioxidant and skin forming resistant properties prepared by sequentially contacting a sulfurized normal calcium alkylphenolate with a calcium alkoxyalkoxide and then Water. The sulfurized normal calcium alkylphenolate reactant is preferably prepared by the sequential or simultaneous reaction of an alkylphenol with a calcium alkoxyalkoxide and sulfur, most desirably followed by the sequential treatment of the resultant product with inert gas and carbon dioxide after removal of any excess unreacted reactant. Both reactions are preferably conducted in a lubricating oil.

BACKGROUND OF INVENTION Field of invention This invention is in the field of art relating to fluent compositions specialized and designed for the use of between two relatively moving surfaces in contact therewith for reducing friction therebetween and preserving the surface. The lubricant compositions of the invention contain a compound whi h has a calcium component linked to a carbon through an oxygen.

Prior art It is well known that lubricating oils tend to deteriorate under the conditions of use in present day diesel and automotive engines with attendant formations of sludge and lacquer and resinous materials which adhere to the engine parts, particularly the piston ring, groove and skirt, thereby lowering the operating efficiency of the engine. To counteract the formation of these deposits certain chemical additives have been found which when added to lubricating oils have the ability to keep the deposit forming materials suspended in oil so that the engine is kept clean and in efficient operation condition for extended periods of time. These agents are known in the art as detergents or dispersants. Metal organic compounds are particularly useful in this respect. These metal organic compounds are considered to be eifective because they provide alkalinity to neutralize strong organic and inorganic acids and are capable of dispersing deposits and deposit precursors into the oil phase. Overbased sulfurized metal alkylphenolates have been found to be particularly effective dispersants in lubricating oils.

Hereinbefore and hereinafter by the term overbased it is meant that the ratio of the number of equivalents of calcium moiety to the number of equivalents of phenol moiety is greater than 1, i.e., the calcium metal ratio is greater than 1. In contrast, the equivalent ratio of calcium to phenol moiety in normal sulfurized calcium alkylphenolate is l;1, i.e., a calcium metal ratio of l.

The prior art teaches many types of overbased sulfurized calcium alkylphenolates and methods of preparation therefor. For example, one prior art procedure is exemplified in US. 2,916,454 which teaches a method of forming overbased sulfurized sodium, barium and magnesium nited States Patent 0 3,474,035 Patented Oct. 21, I969 "ice alkylphenolate lubricating compositions comprising reacting in a lubricating oil medium an alkylphenol with sulfur dichloride and excess sodium, barium or mag nesium alkanolate. The resultant mixture is carbonated to form the overbased salt. The patent also teaches that only sodium, barium and magnesium have been found to provide high metal content phenolate sulfide salt products.

In another prior art teaching US. 3,194,761 discloses the manufacture of lubricating oil compositions containing overbased sulfurized calcium alkylphenolate comprising introducing CO into a mixture of lubricating oil and a sulfurized normal calcium alkylphenolate at an elevated temperature, reacting the resultant admixture with ethylene glycol and calcium hydroxide to form the overbased carbonated salt. The sulfurized normal calcium alkylphenolate reactant is taught to be manufactured by heating together a mixture of lubricating oil, alkylphenol, calcium hydroxide, elemental sulfur and a glycol.

SUMMARY OF INVENTION The subject invention relates to a lubricating composition comprising a hydrocarbon oil of lubricating viscosity containing between about 0.1 and Wt. percent of a high temperature alkaline dispersant consisting of a novel partially hydrolyzed overbased sulfurized calcium alkylphenolate having antioxidant and resistance to skin formation properties which further is not required to be in a carbonated form in order to promote a high degree of overbasing. In the past it was believed in order to form a stable, non-gelling or non-skin forming highly overbased sulfurized calcium alkylphenolate, it was often necessary to form a carbonated product.

Broadly, the dispersant component is prepared by contacting a sulfurized normal calcium alkylphenolate with a calcium alkoxyalkoxide to form an overbased product having a calcium metal ratio of from 1.1 to about 3.5 and then contacting the product with water in a manner to effect between about 20 and 70% of the overbased product followed by the substantial removal of any unreacted water.

A material feature in the dispersant preparation is the water contacting step. In the absence of between about 20 and 70% hydrolysis an unstable overbased product is formed which produces undesirable oil insoluble surface skin (scum) which eventually leads to complete solidification of the additive. Further, when underor overhydrolyzed overbased sulfurized calcium alkylphenolate additive is incorporated into lubricating oils at effective concentrations, the resulting blends undesirably turn hazy with eventual additive separation. Substantial removal of unreacted water from the final reaction mixture is desirable to prevent said water from causing an overhydrolysis (i.e., greater than 70%) of the additive.

DETAILED DESCRIPTION OF THE INVENTION 1 (slL Q (s +t/ R R with a calcium alkoxyalkoxide characterized by the formula Ca{-OA-OR') where A is a divalent saturated aliphatic hydrocarbon radical (alkanediyl) of from 1 to 6 carbons, R' is alkyl from 1 to 25 carbons, to form a first reaction mixture. In the above normal phenolate reactant R is a monovalent saturated aliphatic hydrocarbon radical (alkyl) of from 4 to 100 carbons, x is an average integer of from 1 to 4 and y is an average integer from to 10. It is to be noted x and y are defined as average integers since sulfurized normal calcium alkylphenolate is in essence a complex mixture of monosulfide and polysulfides or a mixture of polysulfides as theoretically defined. In any case the R group is mainly in the para position with the sulfur links mainly in the ortho position. Further, there is probably also a significant amount of covalent character to the calcium-oxygen bond.

The first contacting is advantageously conducted at a temperature between about 10 and 200 C. for a period of time (e.g. 0.001 to 10 or more hours) utilizing a mole ratio of normal sulfurized calcium alkylphenolate to alkoxide reactant of between about 1:01 and 1:25, preferably between about 1:1 and 1:2. The lubricating oil medium advantageously constitutes between about 10 and 90 wt. percent of the first reaction mixture, preferably between about 30 and 70 wt. percent resulting in final lubricating oil concentrate products containing an overbased calcium salt concentrate of between about 10 and 90 wt. percent, preferably between about 30 and 70 wt. percent.

Under preferred conditions, any unreacted materials at the reaction temperature such as a volatile alcohol diluent for the alkoxide reactant are removed e.g. by stripping the first reaction mixture, for example, by passing an inert gas therethrough (e.g. nitrogen) at the distillation temperature of the volatile materials or thereabout.

The stripped or unstripped first reaction mixture is then second contacted with water for a period of time, e.g., between 0.1 and 10 hours at a temperature between about 10 and 250 C., preferably between about 90 and 175 C., advantageously utilizing a mole ratio of water to alkoxide reactant of between about 10021 and 02:1. In any case the second contacting is continued until the overbased sulfurized calcium alkylphenolate is between about and 70% hydrolyzed.

Residual unreacted water is then at least substantially removed from the final reaction mixture by standard means such as inert gas (e.g. nitrogen) stripping at elevated temperature, e.g., 125250 C. By at least substantial removal of water it is intended to denote removal of water to the extent that less than about 1 wt. percent water exists in the final reaction mixture.

The crude product may be further purified by standard means such as distilling of any volatile diluent and byproduct such as alkoxyalkanol which is not removed during the excess water removal step and filtering the residue, e.g., through a standard pressure filter plate at about 20 to 200 C. under between about 0'1 to 100 p.s.i. pressure utilizing a diatomaceous earth filter aid.

It is to be noted the extent of hydrolysis is time, temperature and reactant ratio dependent, therefore, periodic sampling and analysis of the overhead and/or reaction mixture is necessary to determine the extent of hydrolysis. As a practical matter, once the amount of hydrolysis is decided upon the particular set of conditions to produce the desired degree of hydrolysis for a given reactor can be readily determined. With such a determination the need for periodic sampling becomes unnecessary.

In the foregoing procedure it is theorized the calcium alkoxyalkoxide complexes with, or is dispersed by the sulfurized normal calcium alkylphenolate and the water hydrolyzes a portion of the complex calcium alkoxyalkoxide moiety with about 50% hydrolysis of said moiety being the optimum in respect to stability of the product at high metal ratios.

The following theoretical equations further describe the preparation of the hydrolyzed overbased sulfurized calcium alkylphenolate component of the compositions of the invention. It is to be noted Q below is theorized sulfurized normal alkylphenolate as heretofore defined.

In the foregoing equations R and A are as heretofore defined, n is an average integer from about 0.2 to 1.-land m is an average integer from 0.1 to 2.5. Under preferred circumstances n is an average integer between about 0.8 and 1.2.

In the foregoing procedure there are several material aspects:

In the first place, it is necessary for the overbased product to be a sulfurized product otherwise the final product is significantly less stable. Further, attempts to hydrolyze the product without sulfurization will un desirably end in gelled product.

A second materiality is in the use of the calcium alkoxyalkoxide reagent as defined. If calcium hydroxide is substituted therefor, an overbased product cannot be formed which is dispersible in a lube oil solution unless carbona tion is employed.

Another materiality is to utilize less than about 2.5 moles of calcium alkoxyalkoxide reactant per mole of sulfurized normal calcium alkylphenolate. If greater than about the 2.5 maximum mole ratio is employed an overbased product having a calcium metal ratio greater than about 3.5 (i.e. where m. in the aforedescribed equations is substantially greater than about 2.5) will result and the final hydrolyzed overbased sulfurized calcium alkylphenolate will form an undesirable surface skin even with hydrolysis. In addition, if less than about 0.1 mole of calcium alkoxyalkoxide reactant per mole sulfurized normal calcium alkylphenolate reactant is employed. there is no significant increase in eifectiveness over the normal salt precursor.

As a fourth materiality the calcium alkoxyalkoxide moiety of the overbased product in the composition of the invention should be at least about 20% hydrolyzed and not more than 70% hydrolyzed in the interest of retaining fluid stability. As heretofore stated the hydrolysis step appears to be a reaction which is time, temperature and reactant ratio dependent. For example, for a given time period at room temperature a 10-fold mole excess of water in respect to calcium alkoxyalkoxide gives less than 50% hydrolysis, while at 93 C. a 50'300% mole excess gives about 50% hydrolysis, and at 177 C. and thereabove as little as 10% or no excess of water gives about 50% hydrolysis. During hydrolysis it is preferable to control the additional rates of water together with sufiicient agitation to prevent local concentration effects which result in the undesirable formation of large particles of insoluble products. Also, since the temperature of hydrolysis contemplated includes temperatures above the boiling point of water, it is necessary to employ techniques to permit sufiicient time for water contact. Examples of such techniques are the use of superatmospheric pressure and preferably the introduction of water or steam into the reaction mixture via an entrance situated near or at the bottom of the reactor. In regard to the use of steam, it has been found steam hydrolyzed products tend to result in a final product more readily filterable.

Still another materiality is at least the substantial removal of water at the end of hydrolysis in order to insure against over-hydrolysis of the product during storage and/ or use.

In a preferred embodiment the sulfurized normal cal cium alkylphenolate reactant is prepared in the following manner:

The first stage comprises contacting, preferably in a hydrocarbon lubricating oil medium advantageously constituting between about and 70 wt. percent of the final reaction mixture, an alkylphenol of the formula:

where R is as heretofore defined with calcium alkoxyalkoxide of the formula: Ca-tO-AOR') where A and R are as heretofore defined at a temperature between about 0 and 150 C., utilizing a mole ratio of alkylphenol to calcium alkoxyalkoxide of about 2 to form a normal calcium alkylphenolate characterized by the formula:

Prior to the next stage of the reaction the alkoxyalkanol solvent (if used) and by-product is preferably removed from the reaction mixture by standard means such as stripping with an inert gas (e.g., nitrogen) at the temperature of distillation for said alcohol. The purpose of the stripping is to prevent sulfur contamination of the alkoxyalkanol by-product which unless removed would take place in the next stage.

To the stripped or unstripped reaction mixture in the first stage there is charged at a temperature of between about 75 and 250 C. sulfur in a mole ratio of sulfur to normal calcium alkylphenolate of between about 0.15:1 and 8:1, preferably between about 0.521 and 3:1. The sulfur is desirably introduced as a slurry in mineral oil in between about 10 and wt. percent concentration. At the end of the sulfur charge the temperature is maintained for a period of time, e.g., between about 1 and 25 hours, preferably under gas stripping conditions to remove volatile sulfur 'by-products. The resultant product is sulfurized normal calcium alkylphenolate having a sulfur content of between about 0.1 and 10 wt. percent and a calcium metal ratio of about 1.

Under the preferred conditions stripping of the normal sulfurized calcium alkylphenolate with carbon dioxide which is bracketed by inert gas (e.g., nitrogen) stripping is most desirable since carbon dioxide facilitates removal of volatile odorous sulfur byproducts. In addition, the carbon dioxide deodorization treatment of the sulfurized normal calcium alkylphenolate appears to somewhat improve the filterability and stability of the final hydrolyzed overbased product. The inert and CO stripping rate generally employed is between about 0.1 and 10 s.c.f.h./ gallon of reaction mixture at between about 10 and 250 C.

In the aforedescribed procedure for manufacturing the sulfurized normal calcium alkylphenolate reactant it is desirable to first form the calcium alkylphenolate prior to sulfurization or at least simultaneously with sulfurization since alkylphenols do not readily sulfurize.

Alternative means for manufacture of the sulfurized normal calcium alkylphenolate reactant contemplated herein call for reacting alkylphenol with sulfur dichloride with continuous removal of hydrochloric acid by-products and reacting the resultant alkylphenol sulfide with calcium oxide to form the normal sulfurized calcium alkylphenolate as heretofore defined. This alternative procedure although producing the desired product has the undesirable feature of producing hydrochloric acid by-products which requires relatively costly apparatus and handling techniques for removal, and also generally results in the incomplete neutralization of the phenol.

Another alternative procedure for forming the normal sulfurized calcium alkylphenolate reactant is contacting an alkylphenol with calcium oxide or calcium hydroxide in the presence of a glycol such as ethylene glycol to form the calcium alkylphenolate with simultaneous sulfurization. This process has the disadvantage of usually requiring reduced pressure to remove the solvent glycol, thus increasing equipment requirements. Also, the normal sulfurized calcium alkylphenolate prepared in this way retains residual glycol decomposition products which tend to degrade the high temperature dispersant properties of the product.

The content of the aforedescribed hydrolyzed overbased sulfurized calcium alkylphenolate in the lubricating oil composition of the invention may range anywhere from 0.1 to wt. percent. The higher concentration, e.g., between about 30 and 90 wt. percent are normally found in composition directly from the manufacture of the hydrolyzed overbased phenolate whereas the preferred concentration in final lubricating oil compositions of the hydrolyzed overbased phenolate additive for automotive use is between about 0.1 and 5 wt. percent. In any event, in the entire range the additive in the lubricant compositions of the invention will function as an alkaline dispersant.

In the finished lubricating oil compositions other additives may be included. These other additives may be any of the standard suitable pour depressors, heat thickening sulfurized fatty oils, additional sludge dispersants (e.g., petroleum sulfonates), antioxidants, silver corrosion inhibitors, viscosity index improvers and oiliness agents. Exactly what other additives are included in the finished oil and the particular amounts thereof will, of course, depend on the particular use and conditions desired for the finished oil product.

Suitable base oils useful in the compositions of the invention as well as diluent in the manufacture of the hydrolyzed overbased sulfurized calcium alkylphenolate component include a wide variety of hydrocarbon lubricating oils such as naphthenic base, paraffinic base and mixed base mineral oils or other hydrocarbon lubricant, e.g., lubricating oils derived from coal products and synthetic oils, e.g., alkylene polymers, such as polypropylene and polyisobutylene of a molecular weight between about 250 and 2500. Advantageously, lubricating base oils having an SUS viscosity at F. between about 50 and 2000 are employed.

Examples of the alkylphenol reactants contemplated herein are 4-octylphenol, 4-tertiary octylphenol, 2-decylphenol, 2-dodecylphenol, 4-hexadecylphenol, 2,4-didodecylphenol, 2-nonylphen0l, 4-tricontylphenol, 4-eicosylphenol, a mixture of a decylphenol and dodecylphenol (C -C alkylphenol) and mixtures of 2 and 4 positioned monoalkyl and dialkylphenol. It is to be noted the alkylphenol employed will normally be a para alkylphenol. However, 2,4-substituted diakylphenols may also be employed. The only restriction is one ortho or para position of the alkylphenol reactant is desirably available for sulfurization.

Examples of the calcium alkoxyalkoxide reactants contemplated herein are calcium Z-methoxyethoxide, calcium l-methoxypropoxide, calcium S-methoxybutoxide, calcium ethoxy-Z-ethoxide and calcium 4-dodecoxyhexoxide. In order to facilitate reactant contact With the calcium alkoxyalkoxide reactant is preferably employed in conjunction with volatile solvent therefor such as the corresponding alkoxyalkanols such as 2-methoxyethanol, 3-methoxypropanol, and l-ethoxyethanol. The calcium alkoxyalkoxide reactant concentration in the solvent solution is normally between about 20 and 60 wt. percent although higher and lower amounts may be employed.

The calcium alkoxyalkoxide reactant is prepared by standard means such as reacting calcium metal, calcium hydride or calcium carbide with the cor-responding alkoxyalkanol desirably at a temperature between about and 150 C. Of the inorganic calcium reactants, calcium carbide is preferred for economic reasons.

Examples of the sulfurized normal calcium alkylphenolate reactants based on the theoretical formula:

are where R is 4-octyl, x is 1 and y is 0; R is 4-dodecyl, x is 1 and y is l; R is 4-eicosyl, x is 3 and y is R is 2,4-didecyl, x is 2 and y is 3; and mixtures thereof. It is to be noted x and y are defined as average integers.

The following examples further illustrate the invention but are not to be construed as limitations thereof.

EXAMPLE I This example illustrates the preferred preparation of sulfurized normal calcium alkylphenolate reactant.

To a 50 gallon reactor fitted with a variable speed stirrer and means for heating, collecting volatile overhead and purging with gases, there was charged 124 lbs. (0.42 mole) of 4-C C alkylphenol and 120 lbs. of paralrinic base lubricating oil having an SUS viscosity at 100 F. of about 100. The resultant mixture was heated from ambient to 165 C. over a period of 2 hours while passing nitrogen therethrough at a rate of 0.1 s.c.f.h./lb. mixture. At this point, 106 lbs. (0.21 mole) of a 38 wt. percent calcium 2-rnethoxyethoxide in methoxyethanol were added and the temperature and nitrogen blowing was continued over a period of an additional 2.5 hours while distilling off methoxyethanol solvent and by-product. At the end of the 2.5 hour period there was charged to the residue 16.8 lbs. (0.525 mole) of a 46 wt. percent sulfur in a lubricating oil slurry, said lubricating oil having a viscosity of about 100 SUS at 100 F., and the temperature was raised to and maintained at 180 C. for a period of 4 hours with N continuing at a rate of 0.1 s.c.f.h./lb. Then for deodorization 6 lbs. of CO were blown in over 4 hour period, followed by N at 0.4 s.c.f.h./lb. for 1 hour. The stripped mixture was filtered through a pressure filter at 140 C. under 10 p.s.i. utilizing 2.8 lbs. diatornaceous filter aid. The recovered filtrate (280 lbs.) gave the following analysis.

Table I Test: Result Calcium, wt. percent 2.95 Sulfur, wt. percent 2.7 TBU (H010 titration) 81.4

Specific gravity 60/60 0.9715

Viscosity, SUS 210 F 127 Flashpoint, F 360 Sulfated ash, wt. percent 9.7

Total base number.

The filtrate was determined to be a lubricating oil solution containing 50 wt. percent sulfurized normal calcium 4-C C alkylphenolate having a calcium metal ratio of 1 EXAMPLE II resultant mixture was nitrogen blown at a rate of 100 ml./min. while heating to C. Then 478 mls. (26.5 moles) of water in 500 mls. of 2-methoxyethanol were continuously introduced into the reaction mixture at 90 C. over a period of A2 hour. The reaction mixture was then nitrogen blown mL/min.) for a period of 3 hours at 90 C., then stripped of excess water and solvent at 180 C. utilizing 500 N m1./min. At the end of 3 /2 hour period at 180 C. the mixture was filtered through a heated funnel under mild vacuum (18 mm. Hg) utilizing 5 0 g. diatomaceous earth filter aid.

The filtrate was identified as a lubricating oil solution containing 45 wt. percent overbased sulfurized calcium 4-C C alkylphenolate which is about 50% hydrolyzed having a calcium metal ratio of 2. Further analysis found the following.

Table II Test: Result Viscosity, cs. at 210 F. 57.4 Flashpoint, F 375 Calcium, wt. percent 4.4 Sulfur, wt. percent 2.4 TBN (HClO titration) H O, Wt. percent 1 EXAMPLE III Table III PROCEDURAL STEPS Duration,

Hours Temp, C.

sulfurized normal calcium alkylphenolate reactant prep.:

Charge 44310-019 alkylphenol, mineral oil 1. 0 Ambient.

and calcium 2-methoxyethoxide in 2- methoxyethanol. Heat, strip 2-methoxyethanol and nitro- 3.0 Ambient to gen blow. 180. Charge sulfur oil slurry 0.5 180. Strip and nitrogen blow. 4. 0 180. Strip and carbon dioxide blow 1. 0 180. Strip and nitrogen blow 1. 0 180. Hydrolyzed overbased sulfurized calcium alkylphenolate prep.:

Charge calcium 2-methoxyethoxide 1 0 180-150. Strip 2-methoxyethanol and nitrogen blow. 3. 0 180. Charge Water 0.5 180. Strip and Nitrogen blow- 5.0 180. Filter 1 0 Table IIIa! Materials Lbs. Moles sulfurized normal calcium alkylphenolate react. prep.:

1-0-1001; alkylphenol 71. 2 0. 235 Mineral oil 161. 7 2-methoxyethanol, 40.7 62 0 0 n8 3. 5 0. 08 Sulfur 9. 4

Hydrolyzed overbased phenolate product preparation:

Calcium Z-methoxyethoxide, 49.3 136 4 0 059 Z-methoxyethanol, 87.1 Water 4. 66 Diatomaceous filter aid 2. 7

The overbased product was analyzed and the following was found.

9 TABLE IV Tests: Composition Specific gravity 60/60 0.9831 Viscosity, SUS at 210 F. 153 Calcium, wt. percent 5.6 Sulfur, wt. percent 1.9 TBN (HClO titration) 151 The composition was identified as a lubricating oil composition containing 40 wt. percent overbased sulfurized calcium 4-C -C alkylphenolate which is 45% hydrolyzed having a calcium metal ratio of 3.2.

EXAMPLE IV This example demonstrates the oxidation inhibiting effect of the hydrolyzed overbased sulfurized calcium alkylphenolate lube oil composition of the invention. The hydrolyzed overbased products of Examples II and III were subjected to an oxidation test which comprised the following:

The final product composition of Examples II and III were diluted with additional parafiinic lubricating oil until the calcium content is reduced to 0.3 wt. percent. Then 800 cc. of the diluted composition were heated in an oil bath to 300 F. and oxygen at a rate of 3 liters per hour was introduced therethrough while stirring the composition at 300 rpm. At periodic intervals a small amount of the composition was withdrawn and viscosity and neutralization number of the withdrawn product were determined. The degree of oxidation was measured by the degree of viscosity change and the amount the neutralization number increases. As a control a paraifinic base mineral lubricating oil of 695 SUS as 100 F. was tested in which no additives were contained therein. The test results are reported below in Table V.

a Heavy sludge separation during centrifuging prior to testing resulted in artificially low readings for percent increase of centrifuged product.

EXAMPLE V This example illustrates the preparation of sulfurized normal alkylphenolate reactant by an alternative method to the one disclosed in Examples I and III.

To a 300 rnls. reactor fitted with stirrer, addition funnel, thermometer and connected to an aqueous HCl trap there was charged 885 grams (3.0 moles) of 4-C -C alkylphenol and 500 rnls. isooctane. To the resultant mixture 885 g. (2.0 moles) of sulfur dichloride was added with stirring at 1020 C. for a period of 2 hours with the continuous removal of hydrochloric acid by-products. At the end of the reaction the normal solvent was distilled leaving a product identified as 4-C -C alkylphenol sulfide having a sulfur content of 7.0 wt. percent.

To a second reactor there was charged 0.05 g. (0.33 equiv.) of the alkylphenol sulfide formed above, 112 g. diluent mineral oil (100 SUS at 100F.), 9.8 of calcium oxide, 15 g. heptanes and 17 g. methanol. The resultant mixture was heated to 65 C. for 1 hour and then stripped to 180 C. for 4 hours, filtered, giving a sulfurized normal calcium 4-C C alkylphenolate as residue having a calcium metal ratio of about 1 of the following analysis:

10 TABLE VI Test: Result Calcium, wt. percent 2.7 Sulfur, wt. percent 3.1 TBN 74 EXAMPLE VI This example illustrates the formation of a hydrolyzed overbased sulfurized calcium alkylphenolate lubricating oil composition from the sulfurized normal calcium alkylphenolate of the type produced in Example V, except that the sulfurized normal phenolate is not isolated.

To 1286 g. (3.96 equiv.) of 4-C C alkylphenol sulfide of the type produced in Example V, there was charged 2807 g. parafiinic lubricating oil of 100 SUS at 100 F., 376 g. (1.98 moles) of calcium Z-methoxyethanol at a temperature of 20 C. The resultant mixture was heated and stripped with nitrogen blowing to a temperature of 180 C. followed by C0 treatment, and cooling to C. There was then added 2644 g. (4.15 moles) of calcium 2-methoxyethoxide in 2- methoxyethanol solution followed by the addition of 284 g. (15.1 moles) water over a period of one-half hour, the reactor mixture being maintained at 90 C. At the end of the water charge the reaction mixture was stripped and nitrogen blown to a temperature of 180 C. to remove excess water and 2-methoxyethanol solvent. The residual product was a lubricating oil composition containing 40 wt. percent overbased sulfurized calcium 4-C -C alkylphenolate about 50% hydrolyzed having a calcium metal ratio of 3.1. The composition gave the following analysis.

TABLE VII Tests: Results Visc., cs., 210 F. 52.0 Flashpoint, F. 355 Calcium, wt. percent 5.3 Sulfur, wt. percent 1.6 TBN 142 The composition diluted with lubricating base oil to 0.3 wt. percent Ca was tested in accordance with the oxidation test described in Example IV and the following results were obtained:

Data- Product Visc.-increase percent: Ex. VI 1 week 11 2 weeks 34 3 weeks 65 Neut. no. increase percent:

1 week 2.1 2 weeks 4.5 3 weeks 7.1

The base oil employed in the oxidation test was a paraffinic material lubricating oil of an SUS viscosity at F. of 695 containing 2.3 wt. percent of the ethoxylate of polyisobutene (1200 M.W.,) thiophosphonic acid and zinc di-C C alkylbenzene dithiophosphate suflicient to give a zinc content of 0.07 wt. percent.

EXAMPLE VII This example illustrates the criticality of hydrolyzing the overbased product.

The procedure of Examples I and II utilizing the same ingredients procedural steps and approximate quantities with the exception the hydrolysis step was omitted. The overbased product was merely stripped of solvent and filtered. The product had a metal calcium metal ratio of 2 and a calcium content of 4.5 wt. percent. The product formed a light skin overnight on exposure to the atmosphere. In contrast, the final hydrolyzed overbased product of Example II readily filtered and did not form a skin even after about 10 month of storage.

EXAMPLE VIII This example illustrates the criticality in the overbasing step to maintain the mole ratio of calcium alkoxyalkoxide overbasing reactant to sulfurized normal calcium alkylphenolate at less than 2.5 so that an overbased product of a calcium metal ratio of not more than 3.5 is produced.

The procedures of Examples I and II were essentially duplicated with the following exception the reactant quantities were adjusted to give a calcium metal ratio of 4.2 and a calcium content of 6.7 wt. percent in the lubricating oil concentrate in which the hydrolyzed overbased calcium 4-C C alkylphenolate constituted 40 wt. percent of the concentrate. On standing overnight the concentrate formed a skin which did not dissolve on heating or stirring.

EXAMPLE IX This example illustrates the detergent effect of the lubricating oil compositions of the invention.

An example of the composition of the invention and a comparative composition were tested in the well known Caterpillar 1-H Engine Test (Caterpillar Tractor Co.) which is described in FT MS 791a346T and Caterpillar Information Letter No. 46. Performance of the test lubricant is judged by examination of the piston for percent coverage by lacquer and percent of the groove filled with coke. The higher the percentage the less effective the lubricating oil composition from a detergent aspect.

The overbased sulfurized calcium alkylphenolate additive employed in the example composition was of the type produced in Example III, i.e., hydrolyzed overbased sulfurized calcium 4-C C alkylphenolate of calcium metal ratio of about 3 and about 45% hydrolyzed. The base lubricating composition employed consisted of a mineral lubricating oil of an SUS viscosity at 210 F. of about 70.2 wt. percent of the ethylene oxide reaction product of polybutene (1200 M.W.) thiophosphonic acid, 0.07 wt. percent (based on zinc) of zinc isopropyl 1,3- dimethylbutyl dithiophosphate, .05 wt. percent (based on Ca) of calcium hydroxide overbased calcium alkylbenzene sulfonate having a total base number of about 5, .08 wt. percent of a copolymer of dodecyl and octadecyl methacrylates as a pour depressor and 150 ppm. of dimethyl silicon anti-foam concentrate.

To a first portion of the aforedescribed base lubricating oil composition there was incorporated 0.15 wt. percent based on Ca and weight of base composition) of the hydrolyzed overbased sulfurized calcium alkylphenolate of Example 111, thereby forming Test Composition A.

To a second portion of the base lubricating oil composition there was added a well known commercial type detergent additive, namely, 0.15 wt. percent (based on Ca and weight of base comp.) of a calcium carbonate overbased calcium alkylbenzene sulfonate of about 1000 M.W. having a total base number of about 300, thereby forming Comparative Composition B.

The test results are reported below in Table V IH:

TABLE VIII Cat. 1-H Test Inspection after 480 hrs.:

Percent Top Groove Filling 2 Percent 1st Land Coverage Percent 2nd Groove Coverage 3 Comp. A Comp. B

I claim:

1. A lubricating oil composition comprising a hydrocarbon lubricating oil containing between about 0.1 and wt. percent of a between about 20 and 70% hydrolyzed overbased sulfurized calcium alkylphenolate having a calcium metal ratio from 1.1 to about 3.5, wherein said hydrolyzedoverbased sulfurized alkylphenolate is produced by contacting in a hydrocarbon lubricating oil medium a sulfurized normal calcium alkylphenolate having a sulfur content of between about 0.1 and 10 wt. percent and a calcium metal ratio of about 1, and wherein said alkyl group is from 4 to carbons with calcium alkoxyalkoxide of the formula Ca(-O -AOR') where A is alkanediyl of from 1 to 6 carbons and R is alkyl of from 1 to 25 carbons, at a temperature between about 10 and 200 C. and in a mole ratio of said calcium alkoxyalkoxide to said normal alkylphenolate of between about 110.1 and 1:2.5 to form overbased sulfurized calcium alkylphenolate, subsequently contacting said overbased sulfurized calcium alkylphenolate with water at a temperature between about 10 and 250 C. in a mole ratio of water to calcium alkoxyalkoxide of between about 100:1 and 0.2:1 until between about 20 to 70% of said overbased sulfurized calcium alkylphenolate is hydrolyzed, and then substantially removing any residual water.

2. A lubricating oil composition in accordance with claim 1 wherein said sulfurized normal calcium alkylphenolate is sulfurized normal calcium 4-C -C alkylphenolate and said calcium alkoxyalkanol is calcium Z-methoxyethoxide.

3. A lubricating oil composition comprising a hydrocarbon lubricating oil containing between about 0.1 and 90 wt. percent of a between about 20 and 70% hydrolyzed overbased sulfurized calcium alkylphenolate having a calcium metal ratio from 1.1 to about 3.5 wherein said hydrolyzed overbased sulfurized calcium alkylphenolate is prepared by (a) first contacting in a lubricating oil medium an alkylphenol of the formula:

where R is an alkyl of from 4 to 100 carbons with a calcium alkoxyalkoxide of the formula where A is a divalent saturated aliphatic hydrocarbon of from 1 to 6 carbons and R is alkyl of from 1 to 25 carbons in a mole ration of said alkylphenol to said calcium alkoxyalkoxide of about 2:1 at a temperature of between about 10 and 250 C. to form a first reaction mixture containing the corresponding normal calcium alkylphenolate.

(b) subsequently contacting said formed calcium alkylphenolate with sulfur in a mole ratio of sulfur to said alkylphenol of between about 0.15:1 and 8:1 at a temperature between about 75 and 250 C. to form a second reaction mixture containing sulfurized normal calcium alkylphenolate having a sulfur content between about 0.1 and 10 wt. percent,

(c) contacting said sulfurized normal calcium alkylphenolate with an additional amount of said calcium alkoxyalkoxide at a temperature between about 10 and 200 C. in a mole ratio of said sulfurized normal calcium alkylphenolate to said additional calcium alkoxyalkoxide of between about 1:0.1 and 1:2.5 to form a third reaction mixture containing an overbased sulfurized calcium alkylphenolate having a calcium metal ratio of from 1.1 to about 3.5,

13 14 (d) subsequently contacting said overbased sulfurized calcium alkylphenolate with water at a temperature References Cited be tciiveent abtout 2250; C1. a inole rlaktio gf UNITED STATES PATENTS sai wa er sar a mom ca crum a oxya 0x1 e of between about 100:1 and 0.211 until between 2289795 7/1942 McNab 252427 I i 5 2 870134 1/1959 Kluge et a1. 252-42] X about and wt. percent of said overbased sul- 2916454 12/1959 B (H 1 252-42 7 furized calcium alkylphenolate is hydrolyzed, {a et a 3,425,941 2/1969 Kivelevich 25242.7

(e) then substantially removing any residual water. 4. A composition in accordance with claim 3 wherein FOREIGN PATENTS the resultant reaction mixture of steps (a), (b), (c), and (d) are stripped with inert gas at between about 10 942067 11/1963 Great Bntam' and 250 0., wherein said second reaction mixture fol- DANIEL WYMAN primary Examiner lowing said contactin with sulfur is stripped with carbon dioxide and said seco nd reaction and third reaction mix- CANNON Asslstam 'Exammer tures are each filtered following the CO and inert gas 15 v Us Cl XR stripping. 4 252 18 5. A composition in accordance with claim 4 wherein said alkylphenol is 4-C C alkylphenol, said calcium alkoxyalkoxide is calcium Z-methoxyethoxide. 

